400 
Chemical  Notes, 
(Am.  Jour.  Pharm. 
\        Aug.,  1880. 
ganous  chloride.  The  chlorides  of  iron,  manganese  and  lime  are  then 
washed  out  with  water,  and  the  residue  forms  a  concentrated  basic 
phosphate. — Ber.  der  Chem.  Ges.^  xiii,  p.  1150. 
Organic  Chemistry. —  On  Dynamite  Gelatin. — This  new  and  inter- 
esting compound  consists  of  86*4  per  cent,  nitro-glycerin,  9  6  per  cent, 
of  dissolved  gun-cotton,  and  4  per  cent,  camphor.  Despite  the  large 
percentage  of  nitro-glycerin,  it  is, distinguished  by  an  unusual  power  of 
resisting  heavy  blows,  and  it  requires  for  its  explosive  decomposition  a 
cartridge  of  fulminating  mixture,  containing  15  to  20  grams  of  dyna- 
mite. Comparative  experiments  made  in  the  St.  Gothard  Tunne4 
showed  that  the  effective  value  of  dynamite-gelatin  was  more  than 
half  as  much  again  as  that  of  dynamite  No.  i  Thus,  there  proved  to 
be  of  equal  power:  i  part  of  dynamite-gelatin,  i*io  parts  of  nitro- 
glycerin, 1-50  parts  of  dynamite  No.  i,  2*15  parts  of  dynamite  No.  2 
and  3,  and  4*5  parts  of  ordinary  powder. 
Dynamite-gelatin,  in  contact  with  a  burning  body,  burns  like  com- 
mon dynamite  without  detonation.  Two  pieces  of  dynamite-gelatin 
maintained  their  full  explosive  power  even  after  lying  12  days  under 
water.  A  blow  of  20,000  kilograms  per  square  mm.,  struck  by  a 
steam  hammer,  did  not  produce  an  explosion,  even  when  repeated  six 
times;  on  the  contrary,  the  gelatin  began  to  burn. — Chem.  Industrie., 
iii,  p.  173. 
Composition  of  Pyroxylin. — J.  M.  Eder  has  studied  the  properties  of 
five  cellulose  nitrates. 
Cellulose  hexanitrate.,  Cj2Hi^04(N03)g,  is  prepared  by  immersing  dry 
cotton-wool  in  a  mixture  of  3  volumes  of  sulphuric  acid  (sp.  gr.  i  845) 
and  I  volume  of  nitric  acid  (sp.  gr.  1*5)  at  a  temperature  of  10°  for 
24  hours.  The  product  is  thoroughly  washed  with  cold  and  finally 
with  hot  water.  100  parts  of  cotton  yield  fro.ii  175  to  180  of  pyroxylin. 
The  gun  cotton  contains  from  1*2  to  5*8  per  cent,  of  penta- and  tetra- 
nitrate,  which  may  be  removed  by  repeated  digestion  with  a  mixture 
ether  and  alcohol  (3:1).  The  hexanitratc  is  insoluble  in  ether,  alco- 
hol, acetic  acid,  methyl  alcohol,  ethyl  alcohol  and  ^thy.1  acetate^ 
Thoroughly  washed  gun  cotton  may  be  heated, at  100^'  for  several  days 
without  undergoing  any  change  ;  its  temperature  of  ignition  is  between 
169°  and  170°.  Attempts  to  prepare  the  hexanitrate  by  treating  the 
cotton  with  nitre  and  sulphuric  acid  did  not  yield  satisfactory  results. 
Cellulose  pentanitrate^  Ci^Hj-O^' NOs)^,  is  formed  together  with  the 
tetranitrate  by  digesling  cotton-wool  tor  five  hours  at  the  ordinary 
